LONDON (Reuters) - Banks have lined up a $15.6 billion (9.51 billion pounds) financing to back drugs and chemicals maker Merck KGaA’s (>> Merck KGaA) acquisition of U.S. company Sigma-Aldrich Corp (>> Sigma-Aldrich Corporation), banking sources said on Tuesday.

Merck agreed on Monday to acquire Sigma-Aldrich for $17 billion in cash to boost its lab supplies business, the biggest takeover in the German group's history.

Deutsche Bank, JP Morgan and Societe Generale have underwritten the $15.6 billion financing that includes $4 billion of three-year term loans and an $11.6 billion bridge loan that will be refinanced through the bond market, the banking sources said.

The loans will launched for syndication to other banks this week, with a bank meeting due to take place next week, the bankers said.

“There is a lot of liquidity in the loan market at the moment and banks should have good appetite for this deal,” one of the banking sources said.

Merck was not immediately available to comment on the financing details.

Merck said it will acquire Sigma-Aldrich shares for $140 apiece. The deal was approved by Sigma-Aldrich's management but still needs acceptance from more than 50 percent of the target's shareholders.

(Editing by Christopher Mangham)

By Claire Ruckin

Stocks treated in this article : Sigma-Aldrich Corporation, Merck KGaA